As the number of networked computer systems has increased, so has the demand for high-speed networking hardware such as network switches, bridges and routers. Whereas in the past the internal bus speeds of such devices far outpaced the speeds of the networks themselves, today's networks and network switch fabrics are now capable of data transfers that are well within an order of magnitude of the internal bus speeds of the network devices used to interconnect such networks and network switch fabrics. As a result, the performance of network switches, bridges and routers has become an important factor in overall network performance and throughput. Efficient routing and transmission of packets within these network devices can be a significant and even limiting factor in the overall performance of a high-speed network and/or network switch fabric.
One technique that is sometimes used to reduce network traffic and increase network efficiency is to transmit network messages using multicast or broadcast addressing. In such addressing schemes, a single network address is assigned to either a group of devices (multicast) or to all devices (broadcast) within a network address space or sub-network. But the efficiency gains obtained through the use of multicast and broadcast messages can be adversely affected if such messages are transmitted more than once within a network switch, bridge or router. Such redundant transmissions may be necessary if the devices being addressed within the network address space or sub-network are coupled to the network switch through more than one device port.